Cholesterol

Keywords: Total cholesterol, TC, Chol

Specimen:

5 mL blood in EDTA, lithium heparin, or plain tube; consult pathologist. Fasting (14 h) specimen is preferred. Prolonged tourniquet use can artefactually increase levels by up to 20%. See Table1.

Method:

Spectrophotometry.

Reference Interval:

For minimal risk of coronary artery disease, the Australian National Heart Foundation recommends a treatment target of < 4.0 mmol/L.

Application:

Assessment of lipid status, particularly as a risk factor for coronary artery disease.

To assess atherosclerotic risk, cholesterol should be performed with triglyceride and HDL assays, as part of a global risk assessment.

Interpretation:

The optimal level is <4.0 mmol/L and higher levels are associated with an increased risk of coronary artery disease in all age groups. The cause may be primary (familial hypercholesterolaemia and other genetic disorders) or secondary (associated with eg, biliary obstruction, hypothyroidism, nephrotic syndrome).

Levels are reduced for up to 8 weeks with acute illness (eg, myocardial infarction, acute infection) and assessment should not be attempted during this time.

Reference:

Linton MF and Fazio S. Am J Cardiol 2003; 92(1A): 19i-26i.